I have been working with git for just over a month. Indeed I have used reset for the first time only yesterday, but the soft reset still doesn\'t make much sense to me.
Another potential use is as an alternative to stashing (which some people don't like, see e.g. https://codingkilledthecat.wordpress.com/2012/04/27/git-stash-pop-considered-harmful/).
For example, if I'm working on a branch and need to fix something urgently on master, I can just do:
git commit -am "In progress."
then checkout master and do the fix. When I'm done, I return to my branch and do
git reset --soft HEAD~1
to continue working where I left off.